The present invention relates to a sheet metal part having at least one nut element introduced by a riveting process. Such sheet metal parts are well-known in practice and are for example shown in German patent specification 34 47 006, 34 46 978 and in DE-OS 30 16 675.
In the German patent specification 34 47 006, the nut element is formed as a pierce and rivet nut. For this purpose, the nut element has a nut part and a tubular pierce and rivet section which merges via an outwardly directed ring shoulder into the nut part. The nut element is introduced into the sheet metal by means of a stamping head and, indeed, the sheet metal is first pierced by the pierce and rivet section, whereby a stamped slug arises due to the hollow shape of the pierce and rivet section. The tubular pierce and rivet section is subsequently driven through the sheet metal and formed into a turned-over rivet flange at the side of the sheet metal remote from the nut part so that the sheet metal is arranged in form-fitted manner between the turned-over rivet flange and the ring shoulder. Raised features or ribs in the region of the ring shoulder of the nut element are pressed into the sheet metal during this insertion process and form a security against rotation of the nut element, so that on the insertion of a bolt the nut element does not turn relative to the sheet metal.
As can be read in the German patent specification 34 47 006, the stamped slug has to be removed to enable the nut element to be used at all for the intended purpose. This is achieved in that an injection pin is pushed through the threaded bore of the nut element and thereby pushes the slug out of the deformed pierce and rivet section.
Starting from a sheet metal part or a method of the initially named kind, the invention is based on the object of providing a sheet metal part which is particularly suited to be embedded into an injection molded part in that an injection molding composition is injection molded around the sheet metal part, with the plastic composition not penetrating into the thread of the nut element.
It would be possible to satisfy this object in that the nut element is closed off in the injection molding die on both sides, for example, through confronting wall parts of the injection molding die or through special inserts which lie flush against the two end faces of the inserted nut element. This would, however, lead to restrictions in the layout of the injection molding die and to considerable extra complexity and cost so that it can also be seen as a general part of the object underlying the invention to provide greater freedom in the layout of injection molded parts with embedded sheet metal nut elements and also to reduce the complexity and cost in realizing the injection molding and the injection molded part.